I don't wish to start a discussion about focusing screens but to comment my own experience. I never felt the necessity about to change the original focusing screens in my Rollei TLR cameras, BTW I always try to keep clean and usable the system. My Rolleicord IV and 2.8C ground glass screens show a brighter image on the central area than on the edges, I compose the image using the entire screen and I use the central area to focus the subject, it works fine to me. My 3.5F as the other models with interchangeable focusing hood and focusing screen (2.8F,T, E2,E3, Tele, Wide, 'cord Vb, Rolleimagic I and II) have an improved screen that was considered an innovative high tech product when it was released, it's a Fresnel lens and Ground glass combo allowing focusing aids, my original F screen has a central circle with a split horizontal image allowing to focus easily. In the other hand, I have read several negative comments from those no original very bright screens users, they say it's difficult to get the best focusing point in spite of the entire bright image and some users, I think even on this list , preferred to come back to the original screen.- Carlos --- Rollei List - Post to rollei_list@xxxxxxxxxxxxx - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe' in the subject field OR by logging into www.freelists.org - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with 'unsubscribe' in the subject field OR by logging into www.freelists.org - Online, searchable archives are available at //www.freelists.org/archives/rollei_list